Growth on nitrate and occurrence of nitrate reductase-encoding genes in a phylogenetically diverse range of ectomycorrhizal fungi

Abstract

Ectomycorrhizal (ECM) fungi are often considered to be most prevalent under conditions where organic sources of N predominate. However, ECM fungi are increasingly exposed to nitrate from anthropogenic sources. Currently, the ability of ECM fungi to metabolize this nitrate is poorly understood.Here, growth was examined among 106 isolates, representing 68 species, of ECM fungi on nitrate as the sole N source. In addition, the occurrence of genes coding for the nitrate reductase enzyme (nar gene) in a broad range of ectomycorrhizal fungi was investigated.All isolates grew on nitrate, but there was a strong taxonomic signature in the biomass production, with the Russulaceae and Amanita showing the lowest growth. Thirty-five partial nar sequences were obtained from 43 tested strains comprising 31 species and 10 genera. These taxa represent three out of the four clades of the Agaricales within which ECM fungi occur. No nar sequences were recovered from the Russulaceae and Amanita, but Southern hybridization showed that the genes were present.The results demonstrate that the ability to utilize nitrate as an N source is widespread in ECM fungi, even in those fungi from boreal forests where the supply of nitrate may be very low.New Phytologist (2008) 180: 875-889(c) The Authors (2008). Journal compilation (c) New Phytologist (2008) doi: 10.1111/j.1469-8137.2008.02618.x.

Keywords

boreal forest; ectomycorrhizal fungi; nitrate reductase-encoding genes; nar1; nitrate assimilation; nitrate reductase; nitrogen fertilization; nitrogen nutrition

Published in

New Phytologist
2008, volume: 180, number: 4, pages: 875-889
Publisher: BLACKWELL PUBLISHING

SLU Authors

• Lithell, Cajsa

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

• Eberhardt, Ursula

  • CBS-KNAW Fungal Biodiversity Centre

• Karlsson, Magnus

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

• Lindahl, Björn

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

• Parrent, Jeri Lynn

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    
  • University of Guelph

• Taylor, Andy F. S.

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    
  • The Macaulay Land Use Research Institute

UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use
Economics and Business
Social Sciences

Publication identifier

• DOI: https://doi.org/10.1111/j.1469-8137.2008.02618.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/20406